While all states still require children to receive a series of vaccines prior to enrollment - barring any medical exemptions - there are more options now for families to say 'no' to some or all of those shots.

Editor's note: This is a controversial subject for those on both sides of the decision on whether to vaccinate. The goal of KCTV5 News is not to come to a conclusion on who is right. This story is simply meant to shed light on the growing number of families in the country who are making their own minds on whether to get shots or not.

Mandated vaccinations used to be a given right-of-passage for all children preparing to enter school.

While all states still require children to receive a series of vaccines prior to enrollment - barring any medical exemptions - there are more options now for families to say "no" to some or all of those shots.

Like many new parents, Jennifer and her husband, Cole, never had a strong opinion on vaccinations until they were pregnant with their first and began research on everything baby - from cribs, to clothing to immunizations.

Because the couple stepped forward to speak on this controversial topic, KCTV5 News decided not to publish their last name.

"As a parent, you're trying to find the best way to raise your kids," said Jennifer, a Kansas mother.

What they found was something they hadn't heard among the anti-vaccination celebrities, also known as anti-vaxxers.

"Many of the vaccines contained things like frogs, monkey, pork and even human in some cases," Cole said.

Those ingredients conflict with his families Hebrew roots' religious beliefs.

"That was really the end of the line for us. If we're not going to eat it, we're not going to inject it into us for whatever reason," he said.

"I feel our immune systems were created to fight off things very effectively and we need to let them do that," Jennifer said.

While controversial, that decision is gaining traction among parents all across the country.

"There are so many families not getting their children vaccinated," family physician Dr. Shalaunda Gray said.

In her 13 years of practice, Gray spends an increasing amount of time educating patients about vaccine fears.

Many she considers myths, like the fear of the link to autism - a fear that was sparked by a 1998 study in a British medical journal linking the MMR vaccine to autism. It's a study that has since been de-bunked.

"Studies have been done since, numerous studies, that show no link between vaccines and autism. We are very comfortable giving vaccines to children," Gray said.

Take Kansas as an example. In the 2010-2011 school year, 398 children entered kindergarten with an exemption for vaccines. That same number rose by to 481 in the 2012-2013 school year.

Part of the reason for the increase may be the ease at which a parent can opt out.

It used to be parents needed a doctor to sign off on the medical reasons. Now, most states, including Missouri and Kansas, also offer a religious exemption which requires only a parent's signature.

In addition, 18 states have added a philosophical exemption as well.

Many anti-vaxxers are now asking what is the harm.

"If you're worried about your vaccinated child being at risk, what faith are you putting in you vaccine then?" Cole said.

While Gray respects the right to choose, she argues that the logic is flawed because vaccines are not 100 percent.

"Children can get the disease, even though they've been vaccinated," Gray said.

Or, that vaccinated child could carry the disease home to a baby at home who has not yet been vaccinated.

"Not only that child, but also grandma or grandpa who's on chemo or mom who is pregnant and in the first trimester," Gray said. "We are undoing all of the years of protection that we've provided through vaccinations."

That is what many fear is playing out right now.

Just in the last week in Kansas City, there has been a measles outbreak with numerous cases.

California is also in the midst of a large measles outbreak, and Ohio is tackling a large mumps outbreak that medical professionals blame on unvaccinated children.

Nearly two weeks after 16-year-old Amy Yu vanished with 45-year-old Kevin Esterly, the pair was found Saturday in Mexico and the man was arrested, authorities say. (Allentown Police Department)

Nearly two weeks after a 16-year-old Pennsylvania girl vanished with a 45-year-old man, the pair was found Saturday in Mexico and the man was arrested, authorities say. Amy Yu was "unharmed and in good health."

Nearly two weeks after a 16-year-old Pennsylvania girl vanished with a 45-year-old man, the pair was found Saturday in Mexico and the man was arrested, authorities say. Amy Yu was "unharmed and in good health."